Software design method for excitation positive short circuit of generator controller

Abstract

The invention belongs to the field of fault protection of a high-voltage direct-current generator controller, and particularly relates to a software design method for excitation positive short circuit of a generator controller, which comprises the following steps of: setting excitation protection conditions, and when the frequency of a permanent magnet machine is greater than or equal to a network casting rotating speed, a voting unloading signal is network casting permission and a control command of a main contactor is switched on; when the excitation protection condition is met, an excitation over-ground short circuit fault protection mark is set, excitation is removed, and the main contactor is switched off; when it is detected that the excitation positive voltage is normal for a first continuous number of times, eliminating the excitation positive voltage abnormal count and the excitation over-ground short circuit fault mark; and if the frequency of one beat of the permanent magnet machine is smaller than the network casting rotating speed or the voting unloading signal is unloading or the main contactor control command is disconnection, clearing the excitation positive voltage abnormal count, the excitation positive voltage jump count and the excitation over-ground short circuit fault mark. And the continuous short circuit or intermittent short circuit fault of the excitation positive voltage can be accurately identified.

Description

Technical Field

[0001] This application belongs to the field of fault protection for high voltage DC generator controllers, and specifically relates to a software design method for generator controllers regarding excitation positive short circuit. Background Technology

[0002] Based on a systematic study of the fault characteristics of generator controllers in aviation power systems, excitation positive short-circuit faults exhibit two typical failure modes: continuous short circuit and intermittent short circuit. Under continuous short-circuit conditions, the low resistance of the short-circuit loop causes the excitation current to decay below the critical value, resulting in the failure of the generator's magnetic field construction. This directly leads to the interruption of power output from the power system, seriously threatening the power supply stability of critical airborne equipment. Intermittent short circuits, on the other hand, are characterized by the periodic switching of short-circuit states, causing high-frequency oscillations in the excitation current. This, in turn, causes voltage fluctuations in the power system, generating a destructive "beating" effect, accelerating the fatigue aging of mechanical components, and even inducing cascading failure risks.

[0003] Therefore, how to accurately identify and quickly diagnose the two types of short-circuit faults is a problem that needs to be solved. Summary of the Invention

[0004] To address the aforementioned issues, this application provides a software design method for generator controllers regarding excitation positive short circuits, thereby resolving the problem of inaccurate identification and diagnosis of persistent and intermittent short circuits in the prior art.

[0005] The technical solution of this application is: a software design method for a generator controller regarding excitation positive short circuit, comprising:

[0006] Set the excitation protection conditions. When the frequency of the permanent magnet generator is greater than or equal to the grid-connected speed, the voting unloading signal is allowed to be grid-connected, and the main contactor control command is on, and the excitation protection conditions are met, set the excitation ground short circuit fault protection flag, de-excite, and disconnect the main contactor.

[0007] When the first consecutive count of excitation positive voltage is detected as normal, the excitation positive voltage abnormality count and the excitation positive to ground short circuit fault flag are cleared.

[0008] If the excitation positive voltage does not change in the first time, clear the excitation positive voltage jump count and the excitation positive voltage to ground short circuit fault flag.

[0009] If the frequency of the permanent magnet generator is less than the grid-connected speed, or the voting unload signal is unloaded, or the main contactor control command is disconnected, clear the excitation positive voltage abnormality count, excitation positive voltage jump count, and excitation positive to ground short circuit fault mark.

[0010] Preferably, there are two excitation protection conditions, namely:

[0011] The excitation positive voltage abnormality is detected 100 times consecutively. When the excitation positive voltage abnormality is detected, the excitation positive voltage to ground short circuit fault flag is set, and the excitation positive voltage abnormality count is accumulated. After accumulating 100 times, the excitation positive voltage to ground short circuit fault protection flag is set.

[0012] Within 3 seconds, there are 6 changes from abnormal to normal or from normal to abnormal. When the excitation positive voltage jump is detected for the first time, the excitation positive voltage to ground short circuit fault flag is set and a 3-second delay begins. During the delay, the excitation positive voltage jump count is incremented by 1 for each of the above fault phenomena. If the excitation positive voltage jump count is greater than or equal to 6 within the 3-second delay, the excitation positive voltage to ground short circuit fault protection flag is set.

[0013] Preferably, the condition for detecting an abnormal excitation positive voltage is: determine whether the following conditions are met: the excitation positive voltage is ≥ (current frequency value × 0.0638 - 15) V and less than or equal to (current frequency value * 0.0638 + 15) V; if not, the excitation positive voltage is determined to be abnormal.

[0014] Preferably, the specific method for accumulating the excitation positive voltage anomaly count is as follows:

[0015] Determine if the excitation positive transition time has overflowed. If so, clear the excitation positive transition time to zero; otherwise, increment the excitation positive transition time by 1.

[0016] Determine if the excitation positive state is abnormal. If so, increment the excitation positive fault count by 1, clear the excitation normal count to zero, and set the excitation positive fault flag.

[0017] Determine whether the excitation positive state of the previous cycle is different from that of the current cycle. If so, increment the excitation positive transition time by 1; clear the excitation positive stability count to zero and set the excitation positive fault flag; at the same time, store the excitation time of the entire edge of the current cycle into the excitation positive six-time array.

[0018] Determine if the count of positive excitation transition is greater than or equal to 6 times. If so, further determine if the time for 6 positive excitation transitions is less than 3 seconds. If not, set the positive excitation transition fault protection flag.

[0019] Determine if the excitation positive jump count has overflowed. If it has overflowed, increase the current excitation positive jump count by 6 times until the excitation positive fault count is greater than or equal to 100.

[0020] Preferably, when the excitation positive state is determined to be normal, the excitation positive fault count is checked to see if it is not 0. If it is, the excitation positive state is checked to see if it is normal. If it is, the excitation normal count is incremented by 1. Then, the periodic excitation positive state is checked to see if it is the same as that of the current period.

[0021] If the excitation positive fault count is 0 and the excitation positive state is abnormal, then directly determine whether the periodic excitation positive state is the same as that of the current period.

[0022] Preferably, if the periodic excitation positive state is the same as the current period, it is determined whether the excitation positive jump is not 0. If so, the excitation positive stability timer is incremented by 1, and it is determined whether the excitation positive stability timer is greater than 2s. If so, the excitation positive jump count is cleared, the excitation positive stability timer is cleared, the excitation positive fault flag is cleared, and the excitation positive six-time jump time array is cleared. When the excitation positive jump is 0 and the excitation positive stability timer is less than or equal to 2s, it is directly determined whether the excitation positive jump count is greater than or equal to 6 times.

[0023] Preferably, the first number of times is 10 times, the first time is 2 seconds, and the netting speed is 1410Hz.

[0024] The software design method for the generator controller regarding excitation positive short circuit in this application has the following advantages:

[0025] By acquiring electrical parameters such as excitation positive voltage and generator frequency in real time from the generator controller, this method enables accurate identification and rapid diagnosis of two types of short-circuit faults. It can quickly trigger a graded protection mechanism in the early stages of a fault, effectively isolating the fault source, blocking the fault propagation path, significantly improving the fault tolerance and operational reliability of the aviation power system, and providing a solid guarantee for flight safety.

[0026] When the power system has reached the grid-connected state, a dual-parameter joint criterion system of excitation positive voltage and permanent magnet motor frequency is constructed for each fault detection cycle, which can accurately identify continuous or intermittent short circuit faults in the excitation positive voltage. When an abnormal short circuit condition is detected, the system will quickly trigger the protection mechanism to effectively block the abnormal phenomenon caused by the fault, prevent the fault range from expanding, and significantly improve the operational safety and reliability of the aviation power system. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the overall process of this application;

[0028] Figure 2 This is a diagram showing the normal fluctuation range of the excitation positive voltage in this application. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions in the embodiments of this application will be described in more detail below with reference to the accompanying drawings. In the drawings, the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The described embodiments are only some, not all, of the embodiments of this application. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this application, and should not be construed as limiting this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application. The embodiments of this application will be described in detail below with reference to the accompanying drawings.

[0030] The first aspect of this application provides a software design method for a generator controller regarding excitation positive short circuit, wherein when the aircraft is in the power generation grid-connected state, the excitation positive voltage is detected in each fault detection cycle.

[0031] like Figures 1-2 Specifically, it includes the following steps:

[0032] Step 1: Set the excitation protection conditions. When the frequency of the permanent magnet generator is greater than or equal to the grid-connected speed, the voting unloading signal is allowed to be grid-connected, and the main contactor control command is on, and the excitation protection conditions are met, set the excitation ground short circuit fault protection flag, de-excite, and disconnect the main contactor.

[0033] Step 2: When the first consecutive count of excitation positive voltage is detected as normal, clear the excitation positive voltage abnormality count and the excitation positive to ground short circuit fault flag.

[0034] Step 3: If the excitation positive voltage does not change within the first time, clear the excitation positive voltage jump count and the excitation positive voltage to ground short circuit fault flag.

[0035] Step 4: If the frequency of the permanent magnet generator is less than the grid-connected speed, or the voting unload signal is unloaded, or the main contactor control command is disconnected, clear the excitation positive voltage abnormality count, the excitation positive voltage jump count, and the excitation positive to ground short circuit fault mark.

[0036] The above design clarifies the three conditions for entering protection, clearing protection, and exiting protection, forming a closed-loop logic to prevent malfunctions or unrecoverable situations caused by residual protection states. Combining the permanent magnet generator frequency, voting unloading signal, and main contactor status as three conditions ensures that protection is only activated during actual grid operation, avoiding accidental triggering during shutdown or testing phases. Continuous normal monitoring and clearing of the exit state ensure that the system can promptly resume normal monitoring when the fault disappears or operating conditions change, improving availability and reliability.

[0037] Preferably, there are two excitation protection conditions, namely:

[0038] The excitation positive voltage abnormality is detected 100 times consecutively. When the excitation positive voltage abnormality is detected, the excitation positive voltage to ground short circuit fault flag is set, and the excitation positive voltage abnormality count is accumulated. After accumulating 100 times, the excitation positive voltage to ground short circuit fault protection flag is set.

[0039] Within 3 seconds, there are 6 changes from abnormal to normal or from normal to abnormal. When the excitation positive voltage jump is detected for the first time, the excitation positive voltage to ground short circuit fault flag is set and a 3-second delay begins. During the delay, the excitation positive voltage jump count is incremented by 1 for each of the above fault phenomena. If the excitation positive voltage jump count is greater than or equal to 6 within the 3-second delay, the excitation positive voltage to ground short circuit fault protection flag is set.

[0040] The two protection conditions target different fault modes, avoiding the omission or false detection of both types of faults by a single threshold. Continuous short circuits require long-term accumulation of abnormalities to ensure that they are not instantaneous interferences; intermittent short circuits capture the synchronization effect through short-term high-frequency jumps, improving sensitivity to rapidly changing faults.

[0041] Preferably, when the power system is in grid-connected operation, there should be different ranges of excitation positive voltage values ​​depending on the frequency. The conditions for detecting an abnormal excitation positive voltage are as follows: when the excitation positive voltage is less than (current frequency value * 0.0638 - 15) V or greater than (current frequency value * 0.0638 + 15) V, it is considered an abnormal value; when the excitation positive voltage is greater than or equal to (current frequency value * 0.0638 - 15) V and less than or equal to (current frequency value * 0.0638 + 15) V, it is considered a normal value.

[0042] Preferably, the specific method for accumulating the excitation positive voltage anomaly count is as follows:

[0043] Determine if the excitation positive transition time has overflowed. If so, clear the excitation positive transition time to zero; otherwise, increment the excitation positive transition time by 1.

[0044] Determine if the excitation positive state is abnormal. If so, increment the excitation positive fault count by 1, clear the excitation normal count to zero, and set the excitation positive fault flag.

[0045] Determine whether the excitation positive state of the previous cycle is different from that of the current cycle. If so, increment the excitation positive transition time by 1; clear the excitation positive stability count to zero and set the excitation positive fault flag; at the same time, store the excitation time of the entire edge of the current cycle into the excitation positive six-time array.

[0046] Determine if the count of positive excitation transition is greater than or equal to 6 times. If so, further determine if the time for 6 positive excitation transitions is less than 3 seconds. If not, set the positive excitation transition fault protection flag.

[0047] Determine if the excitation positive jump count has overflowed. If it has overflowed, increase the current excitation positive jump count by 6 times until the excitation positive fault count is greater than or equal to 100.

[0048] By accumulating transition times and clearing overflow, the accuracy of the 3-second window is ensured, preventing missed detections or delayed triggering due to timing errors. Three dimensions are distinguished: "abnormal state," "state change," and "transition count," enabling fine-grained tracking of voltage fluctuation patterns.

[0049] Preferably, when the excitation positive state is determined to be normal, the excitation positive fault count is checked to see if it is not 0. If it is, the excitation positive state is checked to see if it is normal. If it is, the excitation normal count is incremented by 1. Then, the periodic excitation positive state is checked to see if it is the same as that of the current period.

[0050] If the excitation positive fault count is 0 and the excitation positive state is abnormal, then directly determine whether the periodic excitation positive state is the same as that of the current period.

[0051] When a normal state is detected, the fault count can be gradually cleared and a stable detection phase can be initiated, forming a smooth transition logic from abnormal to normal. By determining whether the fault count is 0, it is decided whether to immediately enter a state comparison, reducing unnecessary flag switching and lowering software overhead and the probability of false alarms.

[0052] Preferably, if the periodic excitation positive state is the same as the current period, it is determined whether the excitation positive jump is not 0. If so, the excitation positive stability timer is incremented by 1, and it is determined whether the excitation positive stability timer is greater than 2s. If so, the excitation positive jump count is cleared, the excitation positive stability timer is cleared, the excitation positive fault flag is cleared, and the excitation positive six-time jump time array is cleared. When the excitation positive jump is 0 and the excitation positive stability timer is less than or equal to 2s, it is directly determined whether the excitation positive jump count is greater than or equal to 6 times.

[0053] The system maintains a stable timing of >2 seconds before clearing the jump counter and fault flag, filtering out brief normal fluctuations and preventing premature protection termination caused by the instantaneous clearing of fault flags. Once system stability is confirmed, the jump array and counter are automatically reset to free up storage and computing resources, maintaining a lightweight operating environment for long-term software operation.

[0054] Preferably, the first number of times is 10 times, the first time is 2 seconds, and the netting speed is 1410Hz.

[0055] In summary, this application has the following advantages:

[0056] By acquiring electrical parameters such as excitation positive voltage and generator frequency in real time from the generator controller, this method enables accurate identification and rapid diagnosis of two types of short-circuit faults. It can quickly trigger a graded protection mechanism in the early stages of a fault, effectively isolating the fault source, blocking the fault propagation path, significantly improving the fault tolerance and operational reliability of the aviation power system, and providing a solid guarantee for flight safety.

[0057] When the power system has reached the grid-connected state, a dual-parameter joint criterion system of excitation positive voltage and permanent magnet motor frequency is constructed for each fault detection cycle, which can accurately identify continuous or intermittent short circuit faults in the excitation positive voltage. When an abnormal short circuit condition is detected, the system will quickly trigger the protection mechanism to effectively block the abnormal phenomenon caused by the fault, prevent the fault range from expanding, and significantly improve the operational safety and reliability of the aviation power system.

[0058] As one specific implementation method, the following is an illustration using a concrete example:

[0059] In the example, when a positive short-circuit fault occurs in the high-voltage DC power supply system, the generator controller can detect the positive short-circuit fault and report it via communication.

[0060] When no overvoltage, undervoltage, or differential fault is detected, the main contactor is set to enable the connection. When the excitation relay control command is ON, the unloading signal after voting is on, and the permanent magnet generator frequency is greater than or equal to 1410Hz, the main contactor control command is set to ON. At this time, the excitation positive voltage is detected. First, the normal fluctuation range of the excitation positive voltage is determined according to the permanent magnet generator frequency, as shown in Table 1.

[0061] Table 1 Excitation Positive Voltage Range

[0062]

[0063] If the excitation positive voltage is 120V when the permanent magnet generator frequency is 1410Hz, which exceeds the required excitation positive voltage range (75V, 105V) at the 1410Hz frequency, this cycle can be judged as an abnormal excitation positive voltage, and an excitation positive to ground short circuit fault flag should be set.

[0064] Continuous detection is performed in each cycle. When an abnormal excitation positive voltage is detected in a cycle, the abnormal excitation positive voltage count is incremented by 1. When it reaches 100, it is considered that the excitation positive voltage has been short-circuited to ground. The excitation positive voltage short-circuit to ground fault protection flag is set, and the excitation is de-energized and the main contactor is disconnected.

[0065] Furthermore, after an abnormal excitation positive voltage occurs, the normal excitation positive voltage count is set to 0. From the time of the abnormal excitation positive voltage until the fault protection is applied, if the excitation positive voltage recovers to 100V, which meets the required excitation positive voltage range (75V, 105V) at a frequency of 1410Hz, the excitation voltage returns to normal, and the normal excitation positive voltage count is incremented by 1. When the normal excitation positive voltage is detected for 10 consecutive cycles, the previous abnormal excitation positive voltage is considered to be a false sampling or no power-off protection is required. The excitation positive voltage to ground short circuit fault flag is canceled, and the abnormal excitation positive voltage count is cleared.

[0066] In addition to continuous excitation positive short circuits, intermittent excitation positive-to-ground short circuits also exist. When the excitation positive voltage changes from abnormal to normal or from normal to abnormal, it is considered an excitation positive voltage jump. When the excitation positive voltage jumps from 100V to 120V at a frequency of 1410Hz, the first detection of an excitation positive voltage jump is made, an excitation positive-to-ground short circuit fault flag is set, and a 3-second delay begins. During the delay, each time the excitation positive voltage jumps from 100V to 120V (from normal to abnormal) or from 120V to 100V (from abnormal to normal) occurs, the excitation positive voltage jump count is incremented by 1. If the excitation positive voltage jump count is greater than or equal to 6 within the 3-second delay, the excitation positive-to-ground short circuit fault protection flag is set, excitation is de-energized, and the main contactor is disconnected.

[0067] If, during the 3-second delay, there is no transition from normal to abnormal or from abnormal to normal excitation positive voltage within 2 seconds, then the abnormal excitation positive voltage is considered a false sampling or no power-off protection is required. In this case, the excitation positive voltage to ground short-circuit fault flag is canceled and the excitation positive voltage transition count is reset to zero.

[0068] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A software design method for a generator controller regarding excitation positive short circuit, characterized in that, include: Set the excitation protection conditions. When the frequency of the permanent magnet generator is greater than or equal to the grid-connected speed, the voting unloading signal is allowed to be grid-connected, and the main contactor control command is on, and the excitation protection conditions are met, set the excitation ground short circuit fault protection flag, de-excite, and disconnect the main contactor. When the first consecutive count of excitation positive voltage is detected as normal, the excitation positive voltage abnormality count and the excitation positive to ground short circuit fault flag are cleared. If the excitation positive voltage does not change in the first time, clear the excitation positive voltage jump count and the excitation positive voltage to ground short circuit fault flag. If the frequency of the permanent magnet generator is less than the grid-connected speed, or the voting unload signal is unloaded, or the main contactor control command is disconnected, clear the excitation positive voltage abnormality count, excitation positive voltage jump count, and excitation positive to ground short circuit fault mark.

2. The software design method for the generator controller regarding excitation positive short circuit as described in claim 1, characterized in that, There are two excitation protection conditions: The excitation positive voltage abnormality is detected 100 times consecutively. When the excitation positive voltage abnormality is detected, the excitation positive voltage to ground short circuit fault flag is set, and the excitation positive voltage abnormality count is accumulated. After accumulating 100 times, the excitation positive voltage to ground short circuit fault protection flag is set. Within 3 seconds, there are 6 changes from abnormal to normal or from normal to abnormal. When the excitation positive voltage jump is detected for the first time, the excitation positive voltage to ground short circuit fault flag is set and a 3-second delay begins. During the delay, the excitation positive voltage jump count is incremented by 1 for each of the above fault phenomena. If the excitation positive voltage jump count is greater than or equal to 6 within the 3-second delay, the excitation positive voltage to ground short circuit fault protection flag is set.

3. The software design method for the generator controller regarding excitation positive short circuit as described in claim 2, characterized in that, The condition for detecting an abnormal excitation positive voltage is as follows: Determine whether the following conditions are met: excitation positive voltage ≥ (current frequency value × 0.0638 - 15) V and less than or equal to (current frequency value * 0.0638 + 15) V; if not, the excitation positive voltage is determined to be abnormal.

4. The software design method for the generator controller regarding excitation positive short circuit as described in claim 2, characterized in that, The specific method for accumulating the excitation positive voltage anomaly count is as follows: Determine if the excitation positive transition time has overflowed. If so, clear the excitation positive transition time to zero; otherwise, increment the excitation positive transition time by 1. Determine if the excitation positive state is abnormal. If so, increment the excitation positive fault count by 1, clear the excitation normal count to zero, and set the excitation positive fault flag. Determine whether the excitation positive state of the previous cycle is different from that of the current cycle. If so, increase the excitation positive transition time by 1. Clear the excitation positive stability count to zero and set the excitation positive fault flag; at the same time, store the entire excitation time of this cycle into the excitation positive sixth time array; Determine if the count of positive excitation transition is greater than or equal to 6 times. If so, further determine if the time for 6 positive excitation transitions is less than 3 seconds. If not, set the positive excitation transition fault protection flag. Determine if the excitation positive jump count has overflowed. If it has overflowed, increase the current excitation positive jump count by 6 times until the excitation positive fault count is greater than or equal to 100.

5. The software design method for the generator controller regarding excitation positive short circuit as described in claim 4, characterized in that, When the excitation positive state is determined to be normal, check if the excitation positive fault count is not 0. If so, check if the excitation positive state is normal. If so, increment the excitation normal count by 1. Then check if the periodic excitation positive state is the same as that of the current period. If the excitation positive fault count is 0 and the excitation positive state is abnormal, then directly determine whether the periodic excitation positive state is the same as that of the current period.

6. The software design method for the generator controller regarding excitation positive short circuit as described in claim 5, characterized in that, If the positive excitation state of the cycle is the same as that of the current cycle, then determine whether the positive excitation jump is not 0. If so, increment the positive excitation stability timer by 1 and determine whether the positive excitation stability timer is greater than 2s. If so, clear the positive excitation jump count, clear the positive excitation stability timer, clear the positive excitation fault flag, and clear the positive excitation six-time jump time array. When the excitation positive jump becomes 0 and the excitation positive stability time is less than or equal to 2s, then directly determine whether the count of the excitation positive jump is greater than or equal to 6.

7. The software design method for the generator controller regarding excitation positive short circuit as described in claim 1, characterized in that, The first number of times was 10, the first time was 2 seconds, and the net rotation speed was 1410 Hz.

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